Cheilonda Johnson

Association of cross-reactive antibodies targeting peptidyl-arginine deiminase 3 and 4 with rheumatoid arthritis-associated interstitial lung disease

Background A subset of rheumatoid arthritis (RA) patients have detectable antibodies directed against the peptidyl-arginine deiminase (PAD) enzyme isoforms 3 and 4. Anti-PAD3/4 cross-reactive antibodies (anti-PAD3/4XR) have been shown to lower the calcium threshold required for PAD4 activation, an effect potentially relevant to the pathogenesis of RA-associated interstitial lung disease (ILD). Methods RA patients underwent multi-detector computed tomography (MDCT) of the chest with interpretation by a pulmonary radiologist for ILD features. A semi-quantitative ILD Score (range 0–32) was calculated. Concurrent serum samples were assessed for antibodies against PAD by immunoprecipitation with radiolabeled PAD3 and PAD4. Results Among the 176 RA patients studied, any ILD was observed in 58 (33%) and anti-PAD3/4XR was detected in 19 (11%). The frequency of any ILD among those with anti-PAD3/4XR was 68% vs. 29% among those with no anti-PAD (crude OR = 5.39; p = 0.002) and vs. 27% among those with anti-PAD4 that was not cross-reactive with PAD3 (crude OR = 5.74; p = 0.001). Both associations were stronger after adjustment for relevant confounders (adjusted ORs = 7.22 and 6.61, respectively; both p-values<0.01). Among ever smokers with anti-PAD3/4XR, the adjusted frequency of any ILD was 93% vs. 17% for never smokers without the antibody (adjusted OR = 61.4; p = 0.001, p-value for the interaction of smoking with anti-PAD3/4XR<0.05). Conclusions The prevalence and extent of ILD was markedly higher among RA patients with anti-PAD3/4 cross-reactive antibodies, even after accounting for relevant confounders, particularly among ever smokers. These findings may suggest etiopathologic mechanisms of RA-ILD, and their clinical utility for predicting ILD warrants additional study.

A longitudinal cohort study of the anti-synthetase syndrome: Increased severity of interstitial lung disease in black patients and patients with anti-PL7 and anti-PL12 autoantibodies

Objective The aim was to study the prevalence, rate of appearance and severity of clinical features in patients with different anti-synthetase syndrome (ASyS) autoantibodies. Methods All Johns Hopkins Myositis Longitudinal Cohort subjects positive for any ASyS autoantibodies were included. Clinical information, including symptoms, signs, strength, creatine kinase concentrations and pulmonary function tests, were prospectively collected. The standardized mortality and cancer rates and the rate of appearance and intensity of the different organ manifestations were assessed using univariate and multivariate analysis and compared between ASyS autoantibodies. Results One hundred and twenty-four (73.4%) patients were positive for anti-Jo1, 23 (13.6%) for anti-PL12, 16 for anti-PL7 (9.5%) and 3 (1.8%) for anti-EJ or anti-OJ, respectively. The mean length of follow-up was 4.1 years. Anti-PL12 was more frequent in black subjects. Anti-PL12 and anti-PL7 were associated with more prevalent and severe lung involvement, often without muscle involvement. Anti-Jo1 displayed more severe muscle involvement compared with anti-PL12 patients. Concurrent anti-Ro52 was more prevalent in anti-Jo1 patients and was associated with earlier development of mechanics hands, DM-specific skin findings and arthritis. Independent of ASyS antibody status, black patients demonstrated more severe lung involvement than white patients. There was no significant increase in mortality or cancer risk in ASyS patients compared with the general US population. Conclusion Different ASyS autoantibodies are associated with phenotypically distinct subgroups within the ASyS spectrum. Anti-PL7 and anti-PL12 are characterized by more severe lung involvement, whereas anti-Jo1 is associated with more severe muscle involvement. Black race is a major prognostic factor associated with lung disease severity.

Antinuclear Matrix Protein 2 Autoantibodies and Edema, Muscle Disease, and Malignancy Risk in Dermatomyositis Patients

Dermatomyositis (DM) patients typically present with proximal weakness and autoantibodies that are associated with distinct clinical phenotypes. We observed that DM patients with autoantibodies recognizing the nuclear matrix protein NXP‐2 often presented with especially severe weakness. The aim of this study was to characterize the clinical features associated with anti–NXP‐2 autoantibodies.

“Hiker’s feet”: a novel cutaneous finding in the inflammatory myopathies

Mechanic’s hands is a well-characterized manifestation of select idiopathic inflammatory myopathy (IIM) syndromes. Less well characterized is the hyperkeratosis of the toes and plantar surface of the feet that can also accompany these disorders. We aim to describe common pedal signs in the context of IIM, and suggest that it may be another key feature in the presentation of these syndromes. A cohort of 2145 myositis patient charts gathered since 2003 were retrospectively reviewed using the key search terms “mechanic’s feet” and/or “mechanic’s foot.” Charts that included either phrase were further reviewed for clinical characteristics. Nine patients were identified with documentation describing “mechanic’s feet” or “mechanic’s foot.” All nine affected individuals carried a diagnosis of DM, seven of whom also met criteria for antisynthetase syndrome. In eight patients (89%), it presented in conjunction with mechanic’s hands. Six (67%) presented with anti-Jo-1 antibodies, and three (33%) were seronegative. Although the term “mechanic’s feet” has been used to describe this clinical finding in patients in our myositis cohort, we propose the term “hiker’s feet,” given that the presentation resembles a callousing pattern more typical of avid hikers or long-distance walkers. Prevalence data are not yet known but should be considered for further study. If the presenting signs of IIM are expanded to include hiker’s feet, it could aid in not only diagnosis and management but also provide insights into the pathophysiology of these diseases.

Smoking and Subclinical ILD in RA versus the Multi-Ethnic Study of Atherosclerosis

A population-based cohort showed an association between cigarette smoking and subclinical parenchymal lung disease defined as regions of increased computed tomography (CT) lung densitometry. This technique has not been applied to the rheumatoid arthritis (RA) population where associated ILD is highly prevalent. The association between cumulative cigarette smoking and volume of areas of high attenuation (HAA: >-600 and <-250 Hounsfield Units) on full inspiratory CT was compared in 172 RA participants and 3,969 controls in a general population sample. Multivariable regression models were used to adjust for demography, anthropometrics, percent emphysema, and CT parameters. The mean cumulative cigarette smoking exposure was 25 (IQR 10–42) and 15(IQR 5–31) pack-years for the RA and non-RA cohorts, respectively. Mean HAA was 153(±57) cm3 and 129(±50) cm3 in the RA and non-RA cohorts, respectively. Each 10 cigarette pack-year increment was associated with a higher HAA by 0.03% (95% CI, 0.007–0.05%) in RA patients and by 0.008% (95% CI, 0.003–0.01%) in those without RA (interaction p = 0.001). Cigarette smoking was associated with higher lung attenuation; with a magnitude of association more pronounced in those with RA than in the general population. These data suggest that cigarette smoking may be a more potent ILD risk factor for RA patients than in the general population.

Recent advances in the pathogenesis, prediction, and management of rheumatoid arthritis-associated interstitial lung disease.

Purpose of review To provide an overview of recently published articles covering interstitial lung disease associated with rheumatoid arthritis (RA-ILD). Recent findings Over the past year, many studies replicated previous findings in more diverse and occasionally larger populations internationally. Specifically, the association among cigarette smoking, high rheumatoid factor titer, elevated anticitrullinated protein antibody (ACPA) levels, and RA-ILD was strengthened. Clinical characteristics, autoantibodies, and biomarkers to aid in RA-ILD development, progression, and mortality prediction were explored. Finally, direct and indirect treatment effects were highlighted. Summary The ability to identify risk factors for preclinical RA-ILD has been enhanced, but the proper management strategy for these patients is yet to be defined. ACPAs and cigarette smoking are highly associated with RA-ILD, but the mechanistic relationship between lung injury and autoantibody generation remains unknown. There is conflicting evidence regarding the significance of a usual interstitial pneumonia (UIP) versus non-UIP pattern on high-resolution computed tomography. The use of biologic agents in patients with rheumatoid arthritis does not appear to increase the risk of incident ILD or RA-ILD exacerbation. Randomized prospective studies of specific therapy for RA-ILD are still lacking.

Muscular and extramuscular clinical features of patients with anti-PM/Scl autoantibodies

Objective To define the clinical features of myositis patients with anti-PM/Scl-75 and/or anti-PM/Scl-100 autoantibodies at disease onset and during the course of disease and compare them to patients with other forms of myositis. Methods In this longitudinal cohort study, the prevalence and severity of clinical features at disease onset and during follow-up were compared between anti-PM/Scl-positive patients and those with the antisynthetase syndrome (AS), dermatomyositis (DM), and immune-mediated necrotizing myopathy (IMNM). Results Forty-one anti-PM/Scl-positive, 132 AS, 178 DM, and 135 IMNM patients were included. Although muscle weakness was a presenting feature in just 37% of anti-PM/Scl-positive patients, 93% eventually developed weakness. Unlike the other groups, anti-PM-Scl-positive patients had more severe weakness in arm abductors than hip flexors. Interstitial lung disease was a presenting feature in just 10% of anti-PM/Scl-positive patients, but occurred in 61% during follow-up; fewer patients with DM (13%, p < 0.001) and IMNM (6%, p < 0.001) and more patients with AS (80%, p < 0.05) developed interstitial lung disease during the course of disease. Mechanics hands (80%), Raynaud syndrome (78%), sclerodactyly (66%), telangiectasias (66%), esophageal reflux disease (61%), subcutaneous edema (46%), puffy hands (39%), and calcinosis (39%) occurred more frequently in anti-PM/Scl-positive patients than in the other groups. Although 30% of anti-PM/Scl-positive patients met criteria for systemic sclerosis, less than 5% had renal crisis or finger ulcerations. No differences were found between patients with only anti-PM/Scl-100 or only anti-PM/Scl-75 autoantibodies. Conclusions Unlike patients with DM, AS, or IMNM, anti-PM/Scl-positive patients have weaker arm abductors than hip flexors. Anti-PM/Scl-positive patients also have the most extensive extramuscular features.

The Genetics of Pulmonary Fibrosis

The past two decades have been marked by a dramatic increase in the knowledge of the genetics of human disease. The field of interstitial lung disease (ILD) genetics has expanded as well. Much of the early understanding of ILD genetics came from rare Mendelian disorders that were associated with premature onset of disease. Other information came from single-gene multisystem disorders in which lung disease was variably present. More recently, the major advances in ILD genetics have come from focused analysis of familial pulmonary fibrosis. These rare families with multiple members affected by ILD have provided critical new insight into the possible mechanism of sporadic as well as inherited disease. Both linkage studies and large-scale, genome-wide association studies (GWAS) have identified genetic loci implicated in susceptibility to idiopathic pulmonary fibrosis (IPF). The next two decades will surely produce not only new risk alleles but also a more extensive understanding of genetics based on patient molecular phenotyping. In addition, epigenetics remains an area of potential discovery.

Inflammatory Myopathy/Anti synthetase Syndrome

Idiopathic inflammatory myopathy frequently affects the lungs. This chapter focuses on the pulmonary manifestations of patients with myositis. Specifically, we address the epidemiology, clinical and serologic phenotypes, and treatment of myositis associated interstitial lung disease.